Updated HHVM to 3.9.1
Updated HHVM to 3.9.1

ljharb/travis-cookbooks,travis-ci/travis-cookbooks,dracos/travis-cookbooks,ljharb/travis-cookbooks,dracos/travis-cookbooks,gavioto/travis-cookbooks,dracos/travis-cookbooks,ljharb/travis-cookbooks,dracos/travis-cookbooks,gavioto/travis-cookbooks,spurti-chopra/travis-cookbooks,spurti-chopra/travis-cookbooks,travis-ci/travis-cookbooks,gavioto/travis-cookbooks,gavioto/travis-cookbooks,spurti-chopra/travis-cookbooks,travis-ci/travis-cookbooks